All About Darzalex (daratumumab) - Updated 2026

What is Darzalex Faspro or Darzalex. also known as daratoomamab ?  Daratumumab is a monoclonal antibody that recognizes a molecule on the surface of the Myeloma cells called CD 38. Monoclonal antibody means it's in. Antibody, so an immune protein that's produced in the laboratory to just recognize one specific target. And in this case, the target is a molecule that's on the surface, actually of quite a few cells in the body, but specifically on plasma cells, which is the underlying. Antibody producing cells that, uh, make up multiple myeloma when they turn cancerous. And Daratumumab recognizes the CD 38 molecule on the outside of the cells, which then probably attracts other immune cells to attack the myeloma cells, as well as maybe triggering some signaling inside the myeloma cells to result in their death. So it's a very targeted way. Of attacking myeloma cells and Daratumumab actually comes in two formulations. The older Darzalex is an intravenous infusion that takes quite a few hours to administer and has a fairly high rate of infusion reactions, especially with the first dose and the newer Darzalex Faspro is given as an injection under the skin. Takes about five minutes to go in and has much lower rates of infusion reactions so that it's easier and simpler to give. To learn more about monoclonal antibodies be sure to watch HealthTree's lesson on this topic in our antibodies Course  When was daratoomamab first approved? So Daratumumab was first approved in an intravenous formulation in late 2015 based on phase two trials that showed a good response rate in relapsed and refractory multiple myeloma. That then was expanded to a full approval. , as Darzalex in 2016 based on two trials, called Castor and Polls, which combined Daratumumab either with Lenalidomide and Dexamethasone or Revlimid and Dexamethasone or Bortezomib and Dexamethasone, compared to those medications alone and showed improved progression-free and overall survival . How is daratoomamab administered. What is the dose and schedule? these days we're mostly using the subcutaneous or under the skin formulation of Daratumumab, known as Darzalex Faspro. Usually we're giving the under the skin of the belly. It takes about five minutes to infuse all of the medication. It's a reasonable amount of fluid, so it makes a small bump under the skin that then goes down over a couple of hours. The dose is a standard dose for every single patient. It's 1800 milligrams and Darzalex. Fastpro, or Darzalex is usually given once a week for eight doses and then every two weeks for eight doses and then once a month after that. the reason we decrease the frequency is that daratumumab actually, uh, lasts in the body. For weeks after each injections. And so that initial schedule of weekly dosing allows us to build the daratumumab levels in the body up to a high level. But then after that, we don't need to give it as frequently in order to keep the drug levels that high because it does stick around for so long. are there any injection site reactions when daratoomamab is given as a sub-cutaneous injection? Some people will get some redness or irritation or even discomfort at the injection sites for subcutaneous administration of Daratumumab as Darzalex Faspro. Um, it's not very common, but it can happen and it's usually not a major barrier to treatment. According to Darzalex Faspro prescribing instructions the injection is administered into the subcutaneous tissue of the abdomen approximately 3 inches to the right or left of the navel. The injection is given over 3 to 5 minutes. Injection sites should be rotated for successive injections. Do not administer other medications for subcutaneous use at the same site. What is the dose of daratoomamab when administered intravenously? So the docent DAARS Alexis standardized at 16 milligrams per kilogram. So it's based on your body weight and it's consistent through the dosing interval. As long as somebody is on the dose, they get the same. If daratoomamab is being given intravenously, how is the first dose administered? when we give Darzalex, we're very careful on the first dose because of the risk of immune mediated side effects. So that first day can be a long day. It could be an eight, nine, even 10 hour infusion. And it really depends on the tolerability and how the day goes. There are some hospitals and some community settings where people even spend the night in the hospital and they divide the dose over two infusions. Again, really just for safety purposes. Once that first dose is done and people tolerate it, we can speed up the infusion over time. And so the second one may last six hours for. And oftentimes we can get people down to a four hour infusion, which is still a pretty long day. If you think about it, a couple of years ago, my colleagues and I here at Ohio state did a prospective study with what's called rapid infusion. And , we did a clinical trial where we gave patients stars, Alexa, over 90 minutes. And so these are people who had at least three doses and then tolerated the drug well and published this paper several years ago, showing that the 90 minute infusion, is very safe. So in our experience here, we typically, start slowly, make sure everything's well tolerated. And then for most of our patients here, we can speed the infusion up to the 90 minute infusion. This is one of the advantages of the fast pro formulation though, because the shot is generally given over 10 to 15 minutes and people can get in and get out and get on with their day. With less time spent in the. the. One Is intravenous daratoomamab or Darzalex still used? So Intravenous Daratumumab or Darzalex is still available? Most of the time we use subcutaneous administration with the Darzalex Faspro product, but we have a few patients who started getting intravenous Daratumumab and they. Are used to it and prefer to still keep getting it. Occasionally patients have such intense, injection site reactions with the Darzalex faspro that they prefer the intravenous formulation and patients who have a. Port for intravenous administration of medications. Prefer to get the intravenous formulation because they can get just one needle stick to access the port, draw their blood and give the medication infusion, as opposed to having two needle sticks, one for a blood draw, and the second for the Darzalex fastpro administration. Now, most patients would prefer to have two needle sticks and be out of the, infusion center after a five minute subcutaneous injection of Darzalex Spro rather than being at least an hour intravenous infusion of regular Darzalex. So we don't use the intravenous formulation very often, but there are a few patients who end up preferring it. Is the effectiveness of Darzalex and Darzalex Faspro the same? This is a new question card when thinking about Darzalex or Darzalex Faspro, the reason that we use Darzalex Faspro the subcutaneous, uh, injection preferentially, is that it's more convenient. And has fewer injection reaction related reactions. But the effectiveness is basically exactly the same between the intravenous formulation and the subcutaneous formulation. So if for one reason or another you can only get the intravenous formulation, you shouldn't be worried that it's not going to work as well. Is daratoomamab a monotherapy, or used in combination with other antimyeloma therapies? We almost always combine Daratumumab with other effective multiple myeloma agents, especially with proteasome inhibitors like Bortezomib, which is Velcade, or Carfilzomib, which is Kyprolis or with immunomodulatory agents like. Lenalidomide or Revlimid and Pomalyst or pomalidomide. And those combinations, including sometimes four drug combinations like combining Daratumumab with Velcade, Revlimid, and dexamethasone, which is now a standard treatment for initial , therapy for myeloma, are incredibly powerful and lead to very high response rates and very long lasting response. In which patient populations is daratoomamab prescribed. We use Daratumumab now both as part of initial therapy and for relapsed multiple myeloma, especially because it combines so well with other Myeloma agents and because it has such a low level of side effects, , as a drug itself. So it doesn't add much to the side effect profile of a regimen when you combine it to with other drugs. In 2025, we got results of a trial of Daratumumab compared to observation in patients with high risk smoldering myeloma that did show both good response rates. Improved time to progression to active myeloma, and in a preliminary finding, improved overall survival, which is a pretty powerful reason to use a medication. The study wasn't a perfect one, so it didn't. Necessarily show that every patient with high risk smoldering myeloma should receive daratumumab. But we're increasingly offering it as an option to patients who have smoldering Myeloma, no symptoms of active Myeloma, but a high risk of progression as a way of delaying progression and hopefully in the long run, leading to better outcomes. Can daratoomamab be used as a maintenance therapy? Can daratoomamab be used as a maintenance therapy? can it be used as a maintenance therapy? There are some data that suggests that it may be a good idea to use Daratumumab as a maintenance medication after getting an initial response, and especially as part of maintenance therapy after an autologous stem cell transplant. The real proof of that though may come from an ongoing trial, um, that is investigating Daratumumab plus Lenalidomide. Compared to Lenalidomide alone as maintenance therapy, , run by the Southwest Oncology Group or swab. We haven't seen the results of that trial yet, but we're hoping that that will show us not just that daratumumab improves the duration of the response, but that it leads to even better outcomes in the long run by improving overall survival. A list of all approved daratoomamab combinations and indications will be found at the end of this HealthTree lesson. it’s important to know that the daratoomamab schedule can vary slightly depending on which other medicines it’s paired with — what we call the treatment regimen. While the overall pattern is similar, the exact timing and cycle length can change. while the rhythm of weekly, every-other-week, and monthly dosing stays consistent, the cycle structure and the companion drugs are what make each regimen a little different. You can see specific examples of these schedules at the end of this video. What are the infusion related reactions associated with daratoomamab ? So Daratumumab, whether given intravenously as Darzalex or as a subcutaneous injection as Darzalex, faspro can cause what we call infusion reactions, which are typically allergic type reactions, although it's not. Clear that they're a true allergy, and patients can get a fever or chills, itching or hives, shortness of breath or wheezing, sometimes higher, low blood pressures. Those reactions happened very frequently and pretty intensely. When we gave Daratumumab as an intravenous infusion in the subcutaneous version, they happen very infrequently. And only about one out of 10 people gets a reaction almost always with the first dose and almost never with subsequent doses. And those reactions are now pretty mild and tend to get better on their own so that they're not nearly as much of a problem as they used to be. What premedications are used to manage the infusion related reactions. This is the segment that was combined We give pre-medications in part because they might reduce those reactions and because we all remember that when we used to give. The Daratumumab is an intravenous infusion. About half of people got those reactions and they were much more intense. , and we've done that with the subcutaneous Darzalex Faspro, even though the risk of a reaction to the medication is much lower than what we used to see with the intravenous administration, but we're still very careful, especially. First and usually the second doses to give, uh, acetaminophen or Tylenol and diphenhydramine or Benadryl. Um, and usually a steroid medication like dexamethasone as well. We usually give them an hour before the infusion. Wait that hour to make sure those pre-medication have kicked in and then give the subcutaneous or under the skin injection of daratumumab. And then we usually watch people for a couple of hours afterwards because with the subcutaneous Darzalex Faspro, we see that about one out of 10 people will get a reaction, usually within the first couple of hours, sometimes a little bit later on. we only usually do observation after the first dose for two hours and after subsequent doses. We don't think patients need to be observed in the clinic. these days. Will premedications always be necessary? It turns out that after those first couple of doses, the risk of having reaction is dramatically lower, almost zero. And so these days we're usually actually telling patients that they can stop their pre-medication after the first couple of doses because we almost never see reactions. Besides infusion related reactions, what other side effects are common with daratoomamab.  The main other adverse effect of Daratumumab is suppression of the immune system and an increase in the risk of infections. You can definitely see that in the data from randomized clinical trials where some patients got daratumumab and other patients didn't, and you can see that there are more infections in the patients who did get daratumumab. But it's a pretty small increase and most of the infections aren't serious infections, so that although we think that is a real risk of Daratumumab, it's clearly vastly outweighed by the anti myeloma effects of Daratumumab and definitely doesn't stop us from giving the medication. Is I-V-I-G ever considered to help manage infections. We do know that one of the ways that Daratumumab increases the risk of infection is by attacking also normal plasma cells that make normal antibodies to fight off infections and suppressing antibody production. And so certainly for patients who have. At least one severe infection and particularly low antibody levels, which we usually measure by the total IgG level. We do consider giving them antibody infusions as intravenous immune globulin, or IVIG, which is a preparation of antibodies donated by other people, um, that we usually give as an intravenous infusion about once a month. To bump up their IgG levels and give them better protection against infections. It's not usually required for most patients who are getting daratumumab. We use it much more frequently in patients getting even more immune suppressive therapies like those targeted against B-cell maturation antigen or BCMA, which includes CAR T cells and bispecific T-cell engaging antibodies. With Daratumumab, you don't usually see. As much suppression of the immune system, but some people will have low enough IgG levels and enough, experience with infections that we'll end up giving them IVIG infusions to help prevent more severe infections later on. According to the manufacturer's website, the most common side effects associated wth daratoomamab combination therapy include tiredness, nausea, diarrhea, shortness of breath, trouble sleeping, headache, rash, fever, cough, muscle spasms, back pain, vomiting, high blood pressure, muscle, bone, and joint pain, cold-like symptoms, upper respiratory infection, nerve damage causing tingling, numbness, or pain, constipation, lung infection ,pneumonia, swollen hands, ankles, or feet and decreased red blood cell counts These are not all of the possible side effects of daratoomamab combination therapy. Call your doctor for medical advice about side effects. What should individuals who are taking daratoomamab know about blood typing? Daratumumab definitely interferes with cross-match testing for red blood cell transfusions, which means that if you need a transfusion and you're receiving daratumumab and the blood bank does preliminary testing of your blood to see whether you have antibodies. Against other people's red blood cells that would potentially cause a reaction when they give you a transfusion. The Daratumumab will show up on their initial testing as an antibody against other people's red blood cells. It doesn't actually cause red blood cell transfusion reactions, so it's not dangerous to give you a transfusion, even though that testing is showing that possibly it could be dangerous. But the practical effect of that is that it can. It take a long time and a lot of testing for the blood bank to figure out what's going on. If they don't know that you're getting the Daratumumab, if they know that you're on the Daratumumab, most of the time, they can quickly confirm that that's what's going on and quickly get you the transfusion that you need. But if they're not aware of it, say if you've been getting Daratumumab at a different doctor's office or a different hospital and the blood bank at the hospital that's trying to get you your transfusion, isn't aware of it, they can spend hours, 10, 15 hours doing additional testing, which can take a lot of their time and really delay the amount of time until you get the transfusion that you need. So it's really important that if you're on Daratumumab and someone comes to you and says, you need a transfusion, but it's going to take extra time because we found unexpected antibodies that you make sure that they let the blood bank know that you're receiving the daratumumab because there are very quick things that they can do to confirm that and get you the transfusion that you need. Since daratoomamab interferes with routine blood bank testing, your care team will usually determine your blood type and screen for antibodies before you ever receive the drug — in case you need a transfusion later. What should individuals taking daratoomamab know about antibody interference? the Daratumumab can show up as a very low level M spike in the blood, and depending on the type of the patient's. Myeloma M spike, that can cause confusing results 'cause it can make you think that there's a small amount of myeloma protein in the blood when actually it's just the Daratumumab antibody that's showing up on the test. It's not a problem for people who have other types of Myeloma antibodies than the IgG Kappa type, but because the Daratumumab is itself an IgG Kappa antibody, if your myeloma makes IgG Kappa protein and that's the type of your M mpi, you won't necessarily know when the. Serum protein electrolysis or SEP test shows a very low level IgG Kappa protein. You won't know whether that's your myeloma protein or the Daratumumab antibody. Now for many patients, that's not such a big deal because knowing whether there's a very low level M spike or zero M spike doesn't necessarily change how we approach myeloma treatment. But for clinical trials and for certain individual patients where it might make a difference, uh, to know whether you're in a very good partial response or a complete response, there are. Additional tests that can be performed on the serum to try to figure out whether the protein that we're seeing is the Daratumumab or a low level Residual myeloma protein. There's a Daratumumab interference assay that can be run, or the Mayo Clinic has a serum mass spectrometry test that can be run, that can tell the difference between daratumumab and a low level myeloma protein. Approved Darzalex combinations for newly diagnosed multiple myeloma include D-VR dee (Darzalex, Velcade, Revlimid, and dexamethasone), D-Rd (Darzalex, Revlimid, and dexamethasone), and D-VMP (Darzalex, Velcade, melphalan, and prednisone). The regimen selected depends on factors such as transplant eligibility, age, overall health, and treatment goals...   FDA-approved Darzalex combinations for relapsed/refractory multiple myeloma include: • Dee -R dee (Darzalex (plus) lenalidomide (plus)dexamethasone). • Dee be dee (Darzalex (plus) bortezomib (plus) dexamethasone). • D-Pd (Darzalex plus) pomalidomide plus dexamethasone). • Dee K Dee (Darzalex plus) carfilzomib plus) dexamethasone). • D-KR dee (Darzalex plus carfilzomib plus) lenalidomide plus) dexamethasone) and Darzalex monotherapy for patients who have received multiple prior lines of therapy...